Urinary cell-free microRNAs as potential biomarkers of urothelial carcinoma of the urinary bladder
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| Year of publication | 2015 |
| Type | Conference abstract |
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| Description | Introduction: Urothelial carcinoma of the urinary bladder (UCUB) is the most common malignancy of the urinary system. UCUB is divided into muscle invasive and non-muscle invasive bladder cancer (superficial), which represents approximately 80 % of cases. Despite the relatively high degree of superficial tumors is UCUB associated with high local recurrence rate and approximately 20 % of non-muscle invasive tumors progress to invasive form. Although cystoscopy remains a fundamental investigative tool in the detection and surveillance of urothelial bladder cancer, carcinoma in situ (CIS) or small papillary tumors can be with this method easily missed. This has led to the development of newer technologies and several molecular urinary tests, but currently there is no sensitive biomarker enabling early detection of relapse, which occurs in almost 70 % of cases of superficial UCUB or biomarker with ability to predict the risk of progression of non-invasive to invasive form of UCUB. Such requirements could fit with diagnostic approach based on the detection of microRNAs (miRNAs) in urine, where have already showed remarkably high stability and good analytical properties. Patients and methods: Using Affymetrix miRNA microarrays we have analyzed expression profiles of 1733 miRNAs in urine supernatant of 16 UCUB patients (6 invasive, 5 high-grade non-invasive, 5 low-grade non-invasive), 17 controls, 10 RCC patients and 4 urinary tract infections (UTI). Ability of selected miRNAs to identify UCUB from urine was confirmed in the validation phase based on independent cohort of 80 UCUB patients using qRT-PCR method. Results: Global expression profiling revealed set of 76 miRNAs significantly differentially expressed in urine of UCUB patients (P < 0,01) compared to healthy controls, thereof 64 highly up-regulated and 12 down-regulated. These miRNAs were specific for UCUB also when compared to other examined cohorts of patients (RCC, UTI). Moreover 23 miRNAs were able distinguish invasive and non-invasive forms of UCUB (P < 0,01) and 18 miRNAs high-grade and low-grad non-invasive (p < 0,01). Subsequent validation on larger independent cohort of UCUB patients lead to definition of urinary miRNA panel enabling sensitive and highly specific diagnosis of UCUB from urine. Conclusion: Our data have shown that urinary miRNAs could serve as sensitive and specific biomarkers of UCUB and after further independent validations could be useful tool to increase sensitivity of standard cytological examination potentially decreasing high costs for long-term follow-up of UCUB patients. |